Look at the physical component. "B58944" is likely a combination of:
Action: Search for 2SB589 or B589 transistor instead.
| If the component has... | It is likely... | | :--- | :--- | | 3 pins, plastic case | PNP transistor (2SB589) | | 5-7 pins, small IC | Custom driver or logic IC | | Large, metal tab | Power transistor or voltage regulator |
Here is a placeholder datasheet template you can fill in as you find the real document:
| Parameter | Value (when known) | |-----------|--------------------| | Manufacturer | NEC / Renesas | | Part number | B58944 (verify) | | Part family | ? | | Package | ? | | Pin count | ? | | Operating voltage | ? | | Supply current | ? | | Key features | ? | | Datasheet release | 2021 (if confirmed) | | Status | ? (Active / EOL) |
In the realm of electronic components, few model numbers generate as much targeted interest among repair technicians, hardware enthusiasts, and circuit designers as the NEC B58944. While NEC Corporation (now part of Renesas Electronics after a series of mergers and acquisitions) produced thousands of semiconductor devices, the B58944 has maintained a persistent presence in technical forums, repair guides, and parts sourcing discussions well into 2021 and beyond.
This article provides a deep-dive reference for the NEC B58944 datasheet 2021, compiling available technical data, pinout configurations, electrical characteristics, typical applications, and replacement strategies. Given that NEC no longer publishes original datasheets for this legacy component on its primary domain, this guide synthesizes information from archival sources, service manuals, and industry-standard testing data as of the 2021 timeframe. nec b58944 datasheet 2021
From service records and component-level repair logs (2020–2021), the NEC B58944 has been found in:
Look at the actual component marking — not just B58944. Example:
NEC
B58944
123
Check:
Introduction
The NEC B58944 designation refers to a surface-mount light-emitting diode (LED) device produced by NEC (now part of Renesas/ROHM family via mergers and acquisitions in the semiconductor industry). The 2021 datasheet consolidates the device’s electrical, optical, mechanical, and reliability specifications for designers integrating this LED into backlighting, indicator, and general illumination applications. This essay summarizes the device characteristics, explains key parameters, discusses typical applications and design considerations, and examines reliability and sourcing notes relevant to engineers in 2021.
Device overview and purpose
NEC’s B58944 is a small, high-efficiency SMD LED optimized for compact lighting applications where luminous efficacy, color consistency, and thermal performance matter. Typical variants in the B589xx series include different colors (white, red, green, blue, amber) and package sizes; B58944 specifically denotes one part number within that family with a set of nominal color and electrical characteristics defined in the 2021 datasheet. The device is intended for use in consumer electronics (mobile devices, displays, key backlighting), automotive indicators (where AEC or automotive-grade variants exist), and industrial indicators.
Electrical and optical characteristics
Key datasheet parameters designers rely on include: Look at the physical component
Thermal characteristics and derating
Thermal behavior is crucial: the datasheet lists maximum junction temperature (Tj max), thermal resistance from junction to ambient (RθJA) for typical PCB layouts, and recommended maximum ambient temperature and current derating curves. Designers must ensure adequate PCB copper area, thermal vias, and heat sinking for high-current or cluster arrays to maintain lumen output and lifetime.
Mechanical and packaging information
The datasheet includes package dimensions, land-pattern recommendations, tape-and-reel packing details for pick-and-place, and soldering profile guidelines (reflow peak temperatures and time-above-liquidus). Small SMD form factors require precise land patterns to avoid tombstoning and to ensure thermal dissipation.
Reliability, testing, and lifetime
NEC provides reliability test results: forward current life-test data (e.g., L70 or L50 lifetime at given current and ambient), junction temperature cycling, moisture sensitivity level (MSL), and ESD classification. Expected lifetime for typical white SMD LEDs at moderate drive currents and good thermal management is often thousands to tens of thousands of hours; exact numbers depend on operating current and temperature and are presented as measured data and derating guidance in the 2021 datasheet.
Application notes and recommended circuits
The datasheet and accompanying application notes usually recommend:
Quality, compliance, and procurement considerations
Manufacturers list compliance to RoHS and other environmental directives, plus any automotive-grade or AEC-Q certifications for variants intended for vehicles. Binning and traceability details help procure consistent color/flux parts; designers should specify required bins or request matched-bin reels for visible uniformity in assemblies.
Comparisons and alternatives
Within the market, NEC’s B589xx parts compete with similar SMD LEDs from other suppliers (e.g., Nichia, OSRAM, Lumileds). Designers select among suppliers based on luminous efficacy, color quality, thermal performance, available bins, supply-chain stability, and cost. When replacing parts, confirm footprint, Vf, luminous intensity, and chromaticity bins are compatible. Action: Search for 2SB589 or B589 transistor instead
Practical design example (concise)
Assuming a white B58944 driven at 10 mA per LED with typical Vf = 3.0 V and typical luminous flux per LED from the datasheet:
Supply-chain and obsolescence notes (2021 context)
By 2021, supply-chain disruptions affected many semiconductor components; designers should verify lead times and consider multi-sourcing. Also verify whether NEC’s LED lines remained supported under successor companies; cross-reference manufacturer part numbers and authorized distributor availability before committing to a design.
Conclusion
The NEC B58944 as specified in the 2021 datasheet is a compact, efficient SMD LED suitable for a wide range of indicator and backlighting applications. Key design considerations from the datasheet include forward voltage and current ratings, luminous flux/intensity and color binning, thermal management requirements, soldering and handling guidelines, and reliability/lifetime data. For product designs, follow the datasheet’s electrical, thermal, and mechanical recommendations, select appropriate binning for color consistency, and validate parts under your application’s thermal and drive conditions.
Related search suggestions (terms to explore further):
If a real 2021 NEC datasheet for B58944 existed, it would include:
But again: No such public document exists for "B58944" from 2021.
The NEC B58944 is almost exclusively found in a TO-220AB plastic package. In 2021, original NEC-marked units were considered obsolete, but Chinese, Taiwanese, and Korean aftermarket copies were still circulating.